Jae Crowder hit an off-balance fall-away shot from deep on the right wing with .8 seconds left, lifting Boston to a 95-93 win over the Toronto Raptors on Tuesday that secured the seventh seed in the Eastern Conference for the Celtics.
Evan Turner and Avery Bradley each scored 14 points for Boston, which will face No. 2 seed Cleveland in the playoffs. Brandon Bass added 13 points and nine rebounds.
"Hey, to have a chance to compete against the very best in the league is a great opportunity," Boston coach Brad Stevens said. "It's a big mountain, but it is a great opportunity."
It was the fifth straight win for the Celtics, who clinched a playoff spot on Monday when Brooklyn lost.
"It's exactly what we wanted, no matter who it is — whether the Atlanta Hawks or Cleveland," Crowder said.
Kyle Lowry had 16 points for the Raptors, who are currently the fourth seed, but could move up to the third seed.
"The way we lost tonight, we're disappointed," coach Dwane Casey said. "But it doesn't (spoil) the season."
Boston collected 17 offensive rebounds and owned a 50-43 edge on the glass.
"They were crashing the boards really hard," Lowry said.
Lou Williams also had 16 points for Toronto, Terrence Ross scored 12 and Jonas Valanciunas' 11.
After Turner's shot was blocked out of bounds with 2.5 seconds left, Crowder caught the ensuing inbounds pass and nailed the winner.
Lowry's shot at the buzzer was blocked by Turner.
The teams were tied six times in the final quarter before Turner hustled after his own miss and found Tyler Zeller for a one-hander in the lane with 14 seconds left.
Just like a few seconds earlier, Lowry then drove the lane, tying it at 93 with 10.2 seconds to go.
Turner hit a jumper from the right baseline off an inbounds play with 35.2 seconds left to push Boston ahead 91-89, but Lowry scored on a drive down the lane, tying it.
The Raptors had opened an 87-82 lead with 4 1/2 minutes left, but Boston tied it on Marcus Smart's 3 from the right wing.
Trailing by eight early in the second half, the Celtics used a 14-5 run to take a 64-63 lead, their first since the opening quarter. Boston led 73-70 entering the final period.
The Raptors led by seven after one, pushed it to 15 late into the second quarter and held a 53-46 advantage at intermission.
Raptors: G Lowry played his third game after missing seven with back spasms. "I feel a little better," he said after the game. "I feel good. My shots just aren't falling." ... F Amir Johnson returned after missing four with an ankle injury. ... F DeMar DeRozan was given the night off.
Celtics: The team honoured a piece of the club's history: The play when John Havlicek stole the ball to seal the 1965 Eastern Conference final 50 years ago Wednesday. Hall of Famer Havlicek received a standing ovation when he was introduced at centre court after a video of the play was shown on the Jumbotron. ... Bradley limped to the locker room early in the second half with a left leg injury and didn't return. "Everybody I talked to said he's fine," Stevens said. "He will not play tomorrow, though."
Despite having a playoff spot secured, Boston wanted a good showing in its last home game.
"We sent out a text last night, talked about it this morning," Stevens said. "We have an opportunity to compete and when you have an opportunity to compete, you compete as well as you can."
The Raptors (48-33) have one last shot for a club-record 49th win.
Raptors: host Charlotte on Wednesday.
Celtics: at Milwaukee on Wednesday.